The Soler and Palau PER-355 W plastic louvre back draught shutter is designed for 355mm ventilation systems. Its louvre design enables efficient airflow while blocking reverse air movement when the fan is not in operation. Made from durable plastic, the PER-355 W provides reliable, long-lasting performance and protects the ventilation system from external debris and unwanted drafts. Suitable for commercial, industrial, and residential applications, this accessory enhances airflow control and overall ventilation efficiency.